A tape library has physical tape drives, physical slots, and computerized processes that process physical tapes. Conventionally, a tape library has been a target for commands from applications. In response to these commands, the tape library may provide requested data and/or limited information (e.g., status, error signal, capacity information, tape health information). FIG. 1 illustrates a conventional application 100 providing commands to a conventional tape library 110 and receiving data and status in return.
One example tape library is a Scalar I40 tape library, which is a rack-mountable library that uses the LTO (linear tape open) Ultrium 4 recording standard and has a serial attached SCSI (small computer system interface) interface. The I40 may store up to 40 TB on up to 25 removable media which may be, for example, LTO Ultrium media that can store up to 1.6 TB. The I40 may be configured with a display and with a bar code reader.
FIG. 2 illustrates that, more generally, a tape library 200 may include a number of tape drives (e.g., 210, 212, 214, . . . 218) and a number of slots (e.g., 220, 222, . . . 248) that may house tapes. The tapes may be moved back and forth between the slots and the tape drives. The tape drives, slots for storing tapes, and tapes (media) that can be placed in the tape drives can be logically grouped in a logical representation that may be referred to as an application representation. Tape library 200 may present N different application representations to M different applications, N and M being integers. Some tapes and slots in a tape library can be held back as a “carve out” that is not directly visible to or available to an application.
The carve out may be referred to as a library managed partition. In one conventional application, the carve out is used to perform media scanning associated with extended data life management (EDLM). The media scanning may, for example, identify whether a tape is good, is suspect, or has failed. In another conventional application, the carve out may function as an automated media pool that has a few extra slots or tapes just in case a logical representation runs out of space or another potential emergency occurs. In yet another conventional application, the carve out may be used to analyze tapes to discover properties including, encryption level, encryption type, file system type, tape format, and others.
EDLM may include performing different types of scans (e.g., level 1, level 2, level 3) that may take various amounts of time (e.g., 5 minutes, 20 minutes, 120 minutes). EDLM may perform actions that conventionally an application has not necessarily cared about, but that a tape library owner or administrator cared about. For example, EDLM may scan tapes to determine whether they are good, suspect, or failing.
EDLM may be controlled by a policy. A policy may include two parts. A first EDLM policy part may be a control part that identifies facts including, but not limited to, when a tape is to be scanned, how a tape is to be scanned, and which tape is to be scanned. A second EDLM policy part may be a results part that identifies what to do (e.g., notify, report) for different possible scan results (e.g., good, suspect, failed). EDLM policies may be established on a per representation basis.
EDLM may involve multi-level media scanning capabilities for vaulted tapes. EDLM may automate integrity checking of tapes that reside in a tape library (e.g., Scalar i6000), which may improve resiliency. EDLM enables policies to be set to automate scanning of archived data in a tape library. An archived tape can be proactively scanned, regardless of whether it contains primary data or offsite data. When the carve out is available, EDLM may operate concurrently, in the background, to allow tapes to be scanned without impacting regular library operations.